Process for preparing overbased barium sulfonates,products therefrom and use in distillate fuel oils

ABSTRACT

A PROCESS FOR PREPARING OVERBASED BARIUM OLEFIN SULFONATES FEATURING THE USE OF (1) BARIUM SULFIDE TREATED WITH ACETIC ACID, (2) OLEFIN SULFONIC ACIDS, AND (3) SULFUR DIOXIDE; A PRODUCT OBTAINED FROM THIS PROCESS AND THE USE OF THESE PRODUCTS IN DISTILLATE FUELS ARE DESCRIBED.

United States Patent Ofice 3,580,707 Patented May 25, 1971 ABSTRACT OFTHE DISCLOSURE A process for preparing overbased barium olefinsulfonates featuring the use of (1) barium sulfide treated with aceticacid, (2) olefin sulfonic acids, and (3) sulfur dioxide; a productobtained from this process and the use of these products in distillatefuels are described.

BACKGROUND OF THE INVENTION This invention is directed to a method ofpreparing overbased barium sulfonates and their use in distillate fuels.

Processes for preparing overbased alkaline earth oil soluble sulfonatesare available in the art (see e.g. U.S. 2,617,049, U.S. 2,956,018, US.3,027,325, and US. 3,312,618). The principal products disclosed in theart appear to be those prepared from petroleum derived sulfonic acids.These petroleum derived sulfonic acids are in general alkaryl sulfonatesobtained as side products from the sulfuric acid treatment of petroleumhydrocarbons in refining operations.

The term overbased indicates that the resultant product from thesevarious processes contains an amount of alkaline earth metal greaterthan the stoichiometric amount of metal which would be present if theparticular sulfonic acid were fully neutralized. The theory of thisoverbased complex formation is not fully understood. One suggestion hasbeen that the oil soluble sulfonates act as protective colloids ordispersants thus keeping an alkaline earth compound suspended in a fluidcarrier.

A general method of preparing these complexes features the in situformation of a finely divided alkaline earth compound such as CaCO orCaSO in the presence of a petroleum sulfonate in a hydrocarbon medium.This is accomplished by introducing an acidic gas such as carbon dioxideor sulfur dioxide into an alkaline earth containing, petroleum sulfonatedispersion in a hydrocarbon medium. Recent improvements in this processfeature the use of promoters such as low molecular weight alcohols,phenols, amines, and the like.

When barium sulfide is utilized as a barium source, attempting tooverbase by introducing sulfur dioxide gas into the reaction mixturepresents a problem. The problem is that during the course of thisreaction free sulfur is formed. This sulfur is an undesirablecontaminant in the overbased bariumsulfonate product.

It has been discovered that the formation of sulfur during theoverbiasing step using S can be effectively eliminated by treating thebarium sulfide with acetic acid prior to carrying out the overbasingreaction. In addition, the treatment with acetic acid increases theutilization of barium when a crude barium sulfide such as black ash isused as a barium source. The overbased barium sulfonates prepared inthis manner are useful as distillate fuel smoke suppressors; and theseproducts additionally exhibit good resistance to emulsification.

The present invention provides a method of preparing overbased bariumolefin sulfonates featuring the use of barium sulfide treated withacetic acid as the barium source and S0 as the acidic gas. The productsare effective smoke suppressors in diesel fuels.

SUMMARY OF THE INVENTION A process for preparing overbased bariumsulfonates from an olefin sulfonic acid, barium sulfide, acetic acid andsulfur dioxide in the presence of C -C alkanol and water in a hydrogenmedium; the product obtained by this process and its use as a smokereducing distillate fuel additive.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of thisinvention is a process for preparing an overbased barium sulfonate whichcomprises (1) preparing a mixture of barium sulfide in from about toabout 800 parts by weight of C -C alkanol per mole of barium sulfide,adding at least an equimolar amount of water based on barium sulfide andat least 2 moles of acetic acid per mole of barium sulfide,

(2) heating said mixture to reflux and maintaining said temperatureuntil the evolution of H 5 has sub stantially stopped,

(3) adding thereto a mixture of an inert hydrocarbon medium and anolefin sulfonic acid, prepared by sulfonating a mixture of acyclic,monoolefins having from about 12 to about 32 carbon atonas, such thatthe molar ratio of barium sulfide to said sulfonic acid is from about1:1 to about 10:1,

(4) introducing sulfur dioxide gas into the heated mixture of step (3)until the sulfur dioxide efiluent rate is substantially equal to thesulfur dioxide imput rate, and

(5 distilling substantially all the alkanol, acetic acid and water fromsaid mixture.

Barium sulfide in the crude form known as black ash is a most preferredform of BaS.

Olefin sulfonic acids are used in the present process. These sulfonicacids are products obtained on sulfonating olefins. In sulfonating theolefin, any suitable sulfonation process may be utilized. Suitableprocedures are described in the following patents: US. 3,259,645; US.3,337,437; British 1,072,601; French 1,403,407; and French 1,399,570.Olefin sulfonic acids prepared by treating olefins with S0 areespecially useful sulfonic acids.

The olefin sulfonic acids are generally mixtures containing alkenylsulfonic acids, hydroxyalkyl (or -alkenyl) sulfonic acids, disulfonicacids, and 5 and 6 members cyclic inner esters called sultones. Thealkenyl and hydroxyalkenyl (or alkenyl) sulfonic acids generally predominate in these mixtures. The general nature of olefin sulfonationprocesses, mechanisms and product compositions obtained are described inthe journal entitled Hydrocarbon Processing, vol. 47, No. 3, pages109114, March 1968; and the material therein described is incorporatedby reference.

Olefins which are used for preparing the olefin sulfonic acids areacyclic monoolefins having from about 12 to about 32 carbon atoms andpreferably from about 14 to about 32 carbon atoms. By olefins, I meanolefin hydrocarbons. Olefins which are especially useful for sulfonationare synthesized by methods known in the art; for example, they may beprepared by cracking wax parafiins, by dehydrogenating paraffinhydrocarbons or by polymerizing low molecular weight olefins such asethylene or propylene, using Ziegler type catalysts. It is the generalnature of these olefin preparations that mixtures of olefins areobtained. These olefin mixtures can vary widely in Barium sulfide is thereactant utilized in the present process to supply the barium values forthe overbased product. A preferred form of barium sulfide is a crudeproduct obtained in the commercial preparation of barium sulfide byreducing a barium sulfate ore with carbon. This crude product iscommonly called black ash; it ordinarily contains up to about 90 percentbarium sulfide.

Typical analysis of commercial black ash is as follows; all percentagesare by weight.

The ratio of the reactants used in the present process may be varied. Itis essential, however, that a greater than stoichiometric amount, basedon the olefin sulfonic acid value, of the inorganic barium compound beused in the process. The acid value of the olefin sulfonic acid isobtained by determining either the saponification number of acid numberof the sulfonic acid. The saponification number is the number ofmilligrams of potassium hydroxide required to saponify one gram ofolefin derivative; the acid number is the number of milligrams of KOHrequired to neutralize one gram of the sulfonated olefin derivative. Thesaponification number in the case of the olefin sulfonic acid containingonly free sulfonic acids is equivalent to the acid number; and thuseither determination will account for all sulfonic acid values. Thesaponification number rather than the acid number is preferably used forthe olefin sulfonic acids which contain mixtures of sulfonic acids andthe inner ester sultones. From this saponification (or acid) number, thecombining value or acid value of the olefin sulfonic acid is calculated.

The stoichiometric amount of barium sulfide is that amount required tofully neutralize the olefin sulfonic acid. Since the present processproduces an overbased product, that is, one in which more than thestoichiometric amount of barium is present, the amount of barium sulfideused must be greater than the stoichiometric amount indicated above. Ingeneral, from 2 to 20 times the stoichiometric amount of the bariumsulfide is used in the present invention; an amount of from 4 to timesthe stoichiometric amount is preferred. Expressed in moles of olefinsulfonic acid to barium sulfide, ratios of 1:1 up to 1:10 are useful;sulfonic acid to BaS ratios of 1:2 to 1:5 are preferred, and 1:3 to 1:4are most preferred.

The reaction of the present process can be carried out in a suitablehydrocarbon medium. The medium is characterized by being (1) inertduring the process of the reaction and (2) a solvent for the sulfonicacid starting material. It is also preferred that this medium be asolvent for the overbased product which is obtained in the process; andthis hydrocarbon medium should be compatible with distillate fuel oil,and especially diesel fuel. Any hydrocarbon vvhich meets these criteriamay be used. Aromatic hydrocarbons, paraflinic hydrocarbons, olefinichydrocarbons, mixtures thereof, light distillate hydrocarbon oils,distillate fuels, kerosene straight run naphtha, petroleum refinerystreams such as catalytic reformate, thermally or catalytically crackedstreams, alkylated refinery streams, catalytically cracked naphtha andthe like, are useful hydrocarbon media. Benzene, C -C alkylbenzenes suchas toluene, xylene, acetylbenzene, pentylbenzene and the like, C Cparatfins such as hexane, heptane, dodecane and the like, aviationalkylate, light processing oils such as No. 9 oil, pale oil and thelike, catalytic reformate containing over about percent aromatichydrocarbons and the like, and mixtures thereof are some examples ofuseful media.

The amount of hydrocarbon medium used in the process is not critical. Anamount of inert hydrocarbon ranging from about 0.5 to about 10 times theweight of the olefin sulfonic acid can be used.

Alkanols having from about 1 to about 5 carbon atoms are used in thepresent process. The exact function of the alkanol used in the processis not understood; however, the alkanol is required in order for thereaction of the present process to be carried out. Examples of usefulalkanols are ethanol, isopropanol, pentanol-3, amyl alcohol, 'butylalcohol, and mixtures of these alcohols. Methanol is a most preferredalkanol.

The amount of alkanol used may be varied. Generally the barium sulfidereactant is dispersed in the alkanol as an initial step. The amount ofalkanol used is based on the amount of barium sulfide used. Thus,amounts of alkanol ranging from about to about 800 parts by weight permole (167 parts by weight) of barium sulfide are generally used.

Water is also required in the present process. Ordinarily an equimolaramount of water based on amount of barium sulfide is used. A largeramount of water, for example up to 2 times the necessary amount, canalso be used. The water, excess acetic acid (and alkanol) has to bedistilled off as a final step in the process. As a practical matterthen, too large an excess of water is not used. Acetic acid is acritical component of the present invention. At least two moles ofacetic acid per mole of barium sulfide reactant are required in thepresent process. Generally, up to three moles of acetic acid per mole ofbarium sulfide can be used. Amounts in excess of this are ordinarily notrequired. After the barium sulfide, alkanol, water and acetic acid areblended, the mixture is heated generally to the reflux temperature andheld there until evolution of H 8 is substantially complete. v

The process is carried out at elevated temperatures. Reactiontemperatures of about 50 C. and higher are ardinarily used. The reactioncan conveniently be carried out at the reflux temperature. The refluxtemperature, of course, will be dependent upon the particularhydrocarbon medium used, its amount, and the amount of alkanol and waterin the reaction mixture. An upper temperature limit woulld be about C.although higher reaction temperatures may be used. This reactiontemperature is the temperature at which the sulfur dioxide is passedinto the reaction mixture to effect formation of the overbased complex.

The mixture containing the olefin sulfonic acid materal in hydrocarbonmedium, barium sulfide, acetic acid, water and alkanol is subjected totreatment with sulfur dioxide gas; this is the overbasing step. The S0is simply bubbled through the mixture at the aforesaid reactiontemperatures until the S0 input rate is substantially equal to the rateat which the S0 is coming out of the mixture. At this point theoverbasing reaction may be considered complete; ordinarily theoverbasing reaction is completed within about an hour although longerreaction times, e.g. 3 hours, 8 hours, 24 hours, may be used. The inputflow rate of the S0 will, of course, have an effect on the reaction rateand time. This treatment with S0 effectively complexes thestoichiometric excess of barium with the sulfonic acid, thus forming anoverbased barium olefin sulfonate.

The flow of S0 need not be discontinued after the overbasing reaction isconsidered complete. Generally, the S0 flow is decreased at this timeand maintained at this reduced rate while distilling off the Water,alcohol and excess acetic acid.

The process of this invention is ordinarily carried out at atmosphericpressures. However, it can also be carried out above atmospheric.Pressures above atmospheric can be used to advantage to minimize solventloss while carrying out the reaction; higher pressures might also bedesirable when a reaction temperature higher than the reflux temperatureis used to carry out the reaction. The following examples illustrate theprocess of the present invention; all parts are by weight unlessotherwise indicated. The pale oil used in each of the examples is acommercial product identified as Sun Circosol 410 and the naphtha usedis an aviation alkylate.

EXAMPLE 1 A suitable vessel fitted with a dropping funnel, stirrer,thermometer, water collector and condenser was charged with 79.7 parts(0.4 mole) crude barium sulfifide (85% assay) and 100 parts of methanol.About 14.5 parts of water (0.8 mole) was added with stirring, followedby the gradual addition over a 6-minute period of 54 parts (0.9 mole) ofglacial acetic acid. This mixture was refluxed hours (marked decrease inH 8 evolution was noted) and then cooled. To this mixture was added 44.5parts (0.1 mole) of a 0 olefin sulfonic acid (Saponification No.=126),35 parts of pale oil and 180 parts of naphtha; the mixture was refluxedanother 30 minutes. Sulfur dioxide was then bubbled into the mixtureunder reflux for 45 minutes at a rate of about 0.830 part/minute. Themethanol was allowed to distill off and temperature was then raised to147 C. to remove the water and acetic acid (about 140 parts of naphthawas added during this step as a processing aid). The mixture was thencooled and diluted with about 400 parts of benzene. The mixture 'wasthen filtered through a bed of Celite Filter-aid. The solvents wereremoved under vacuum. The overbased barium olefin sulfonate productobtained was a slightly hazy amber liquid. The yield was 166.4 parts.Analysis showed the product contained 30.8% barium (Ba) and 7.5% sulfur(S); infrared spectrum also showed some acetate present.

EXAMPLE 2 A suitable vessel fitted as in Example 1, was charged with 77parts (0.4 mole) black ash (88% assay) and 100 parts methanol. About14.4 parts of water were added with stirring followed by the gradualaddition over an 8-minute period of 72 parts (1.2 moles) of glacialacetic acid. Nitrogen was then passed through the mixture while it wasrefluxed for 5.5 hours. The mixture was cooled. Then a solution of 44.5parts (0.1 mole) of a C olefin sulfonic acid (Saponification No.=12-6)and 180 parts naphtha was added and the mixture was refluxed for another30 minutes. At this time, S0 was passed into the mixture for 75 minutesat the rate of about 0.830 part/ minute. Next, the methanol was allowedto distill off and the temperature was raised to 145 C. to remove theremaining water and acetic acid. The mixture was cooled and it was thendiluted with about 400' parts of benzene. This mixture was then filteredthrough a Celite Filteraid bed. The solvents were removed from thefiltrate under vacuum. A clear, amber, mobile, liquid product wasobtained. Yield was 173.6 parts. Analysis showed 31.8% Ba and 7.4% S,infrared spectrum indicated presence of acetate.

EXAMPLE 3 The process of Example 2 was essentially repeated except that(1) parts of water was used instead of 14.4 parts, (2) 45.5 parts (09'mole) of 91% formic acid was used in place of the acetic acid and, (3)the first reflux period was 14.5 hours. When the S0 treatment was begun,there was immediate evidence of free sulfur forming in the mixture. Thereaction was discontinued. This example is inserted to indicate thecriticality of acetic acid inthe present invention.

8 EXAMPLE 4 A vessel fitted as in Example 1 was charged with 77 parts(0.4 mole) black ash (88% assay) and 100 parts of methanol. Whilestirring about 14.4 parts of water was added followed by gradualaddition of 60' parts (1.0 mole) of glacidal acetic acid over a periodof about 8 minutes. Nitrogen was then passed through this mixture whileit was refluxed for about 5.5 hours. The mixture was then cooled. Asolution of 44.5 parts (0.1 mole) as a 0 olefin sulfonic acid(Saponification No.=126), 25 parts of pale oil and 180 parts of 'naphthawas added and the mixture was refluxed for 30 minutes. Then, S0 waspassed into the mixture at a rate of about 0.830 part/ minute for 75minutes. The methanol was then distilled off. The mixture was thencooled to C. and about 5 parts of water and about 140 parts of naphthawere added and, continuing the S0 flow into the mixture at about 0.1-84part/ minute, the mixture was again refluxed. Twice more whilerefluxing, 5 parts portions of water were added. Then the mixture washeated to 146.5 C. to remove the remaining water and acetic acid. Themixture was then cooled and diluted with benzene. This mixture wasfiltered through a Celite Filter-aid bed; and the solvents were removedunder vacuum. The overbased product obtained was a clear, dark, mobileliquid. The yield was 181.6 parts. Analysis showed it to contain 30.9%Ba and 7.7% S; and the infrared spectrum indicated the presence ofacetate.

In the Examples 1-4, the C olefin sulfonic acid was a product preparedby 50;, sulfon'ation of 0 olefin composition F in Table 2.

EXAMPLE 5 A suitable vessel, fitted as in Example 1, was charged with 77parts (0.4 mole) black ash (88% assay) and parts methanol. About 14.4parts (0.8 mole) of H 0 was added with stirring followed by the gradualaddition over a 5-minute period, of 60 parts (1.0 mole) of glacialacetic acid. While passing nitrogen through, the mixture was refluxedfor 6.5 hours. To this mixture was added 46.8 parts (0.086 mole) of Colefin sulfonic acid (Saponification No.=103, 30 parts of pale oil and180 parts of naphtha; the mixture was then refluxed for 30 minutes.Sulfur dioxide was then passed into the mixture for 68 minutes at about0.830 part/ minute. (It was noted that after 53 minutes the rate of S0input and exhaust were about the same.) The S0 feed was then reduced toabout 0.1 part/minute and the methanol, water and acetic acid weredistilled off. The mixture was then cooled to 85 C., 5 parts of waterand about 35 parts of naphtha were added and the mixture was refluxed;11.8 parts of aqueous material were collected. The mixture was cooledagain and 5 more parts of H 0 were added; 7.5 parts of an aqueousmixture were collected on refluxing. The mixture was cooled a third timeand about 5 parts of water were added; about the same.) The S0 feed wasthen reduced to about fiuxing. The mixture was then heated to C. toremove the remaining water. On cooling, about 200 parts of benzene wereadded. This mixture was then filtered through a bed of Celite Filter-aidon a coarse frit. The solvents were removed under vacuum. The overbasedbarium sulfonate product obtained was a dark, clear fluid. Analysisshowed 33.1% Ba and 8.1% S; infrared spectrum showed presence of someacetate.

EXAMPLE 6 The procedure of Example 5 was repeated except that no paleoil was added. The overbased barium sulfonate product obtained wasextremely viscous; the yield'was 133.05 parts. Analysis showed 40.1% Baand 10.1% S. The infrared spectrum of this product showed some acetatepresent.

9 EXAMPLE 7 The procedure of Example was repeated, but the followingamounts of ingredients were used in place of those in Example 5.

96.25 parts 0.5 mole) black ash 18.0 parts (1 mole) water 72 parts (1.2moles) glacial acetic acid The product obtained was a moderately viscousliquid; the yield was 181.15 parts. Analysis showed 36.5% Ba and 9.0% S.Some acetate was present as shown by the products infrared spectrum.

EXAMPLE 8 A vessel fitted with a dropping funnel, stirrer, thermometerand condenser was charged with 57.8 parts (0.3 mole) of black ash (88%assay) and 100 parts of methanol. About 10.8 parts (0.6 mole) of waterwere added with stirring followed by the gradual addition of 48 parts(0.8 mole) of glacial acetic acid over a 5-minute period. The mixturewas then refluxed for about 7.5 hours. At the end of this time asolution of 42.8 parts of a 013+ olefin sulfonic acid (SaponificationNo.=110), 35 parts pale oil and 180 parts of naphtha was added and themixture was refluxed for 30 minutes. Sulfur dioxide was then passedthrough the mixture at a rate of 0.830 part/minute for 51 minutes; andthen the sulfur dioxide flow was reduced to 0.1 part/minute while themethanol, water and acetic acid were distilled off. The mixture was thencooled, about 5 parts of water were added, the mixture was brought toreflux and the aqueous layer that collected (in the water collector) wasremoved. This treatment (cooling, add 5 parts water, reflux and removethe aqueous layer) was repeated twice more. Then, the S0 flow wasdiscontinued and the temperature was raised to 140 C. to remove theremaining water. On cooling, the product mixture was diluted with about200 parts of benzene. This mixture was then filtered through a bed ofCelite Filteraid. Solvents were removed under vacuum. The resultantproduct obtained was a clear, dark mobile liquid; the yield was 146parts. Analysis showed it to contain 27.7% Ba and 7.1% S. The infraredspectrum of the prod uct showed the presence of some acetate.

The olefin sulfonic acid used in Example 8 was obtained by S0sulfonating the following C olefin composition; all percentages are byweight.

C olefin mixture EXAMPLE 9 A vessel fitted as in Example 8 was chargedwith 78.4 parts (0.4 mole) of black ash (86.5% assay) and 100 parts ofmethanol. About 14.4 parts (0.8 mole) of water was added with stirringfollowed by the rapid addition (1.5 minutes) of 60 parts (1.0 mole) ofglacial acetic acid. The condenser was immediately connected to a gasscrubber containing 314.1 parts of 4 N sodium hydroxide. The reactionmixture was then brought to reflux and at one-hour intervals about a 75gram sample liquid was removed from the scrubber and then about 5 gramsof water were added to the scrubber. Six samples were thus removed overa period of 7 hours.

At the end of this time, a solution of 46.8 parts (0.086 mole) of a Colefin sulfonic acid (Saponification No.=103) in 60 parts of a C olefinwas added and about 16 parts of methanol were added. This mixture wasrefluxed for 30 minutes. Then S0 was passed through the mixture of 0.830part/minute for 78 minutes. About parts of methanol were distilled offat this time to reduce the viscosity of the mixture. The S0 rate wasthen reduced to 0.14 part/minute and the remaining alcohol, water, andacetic acid were distilled 011?. The temperature of the mixture was thenraised to about 140 C. in order to remove the remaining water. Themixture was filtered through a Celite Filter-aid bed; and the solventswere removed under vacuum. The product obtained was a clear, darkliquid. The yield was 168.4 parts. Analysis showed 29.8% Ba and 8.03% S.The infrared spectrum showed the presence of acetate.

EXAMPLE 10 The procedure of Example 8 was repeated except that 30 partspale oil were substituted for the 60 parts of C olefin.

The product obtained was a moderately viscous fluid. The yield was 157.7parts. Analysis showed 32.5% Ba and 8.26% S. The infrared spectrumshowed some acetate present.

The olefin sulfonic acid used in Examples 5-7, 9 and 10 was obtained byS0 sulfonating the 'C -iolefin composition D of Table 1.

EXAMPLE 1 1 A vessel fitted as in Example 1 was charged with 56.4 parts(about 0.3 mole) of black ash (89.6% assay) and 100 parts of methanol.To this mixture a solution of 48 parts (0.8 mole) of glacial acetic acidand 10.8 parts (0.6 mole) of water was added with stirring over a 4-minute period. This mixture was refluxed for about 7 hours. A solutionof 46.75 parts (0.1 mole) of a C 4- olefin sulfonic acid (SaponificationNo.=130), 20 parts pale oil and 180 parts naphtha was added to themixture; and the mixture was refluxed for 30 minutes. Sulfur dioxide Wasthen passed into the mixture for 58 minutes at about 0.830 part/minute.The S0 rate was reduced to about 0.1 part/ minute and the methanol,water, and acetic acid were distilled oil. The mixture was cooled to C.and about 5 grams of water were added. The mixture was then refluxeduntil 8.9 grams of a liquid Was collected in the water collector. Thecollecting of liquid, the water addition and refluxing were repeated twomore times, collecting 7.1 parts of liquid the first time and 6.2 partsof liquid the second time. The total time during which the sulfurdioxide was introduced at the reduced rate during this sequence wasabout 5.5 hours. At the end of this time, the S0 flow was discontinuedand nitrogen was passed through the mixture. The temperature was thenraised to C. to remove the remaining water. On cooling, the mixture wasdiluted with about 200 parts of henzene. The mixture was filtered with abed of Celite Filteraid. The solvents were removed under vacuum. Theproduct obtained was a clear, dark fluid. The yield was 128.8 parts.Analysis of the product showed 30.6% Ba and 7.96% S. The infraredspectrum showed some acetate presence. 1

' EXAMPLE 12 The process of Example 11 was repeated using 79.6 parts(0.4 mole) of black ash, instead of 0.3 mole of black ash and 30 partsof pale oil instead of 20 parts of pale oil.

The product obtained was a clear, dark moderately viscous material. Theyieldwas 160.2 parts. Analysis showed it to contain 33.2% Ba and 8.31%S. The infrared spectrum showed some acetate present.

EXAMPLE 13 A vessel fitted as in Example 1 was charged with 56.4 parts(0.3 mole) of black ash (89.6% assay) and 100 parts of methanol. To thismixture a solution of 48 parts (0.6 mole) of glacial acetic acid andabout 10.8 parts (0.6 mole) of water was added over a 5-minute period.This mixture was refluxed for about 7.25 hours. To this mixture, asolution of 61.1 parts (0.1 mole) of a C -lolefin sulfonic acid(Saponification No.=92), 20 parts pale oil (Sun Circosol 410), and 180parts naphtha (aviation alkylate) was added and the mixture was refluxedfor 30 minutes. S0,, was then passed into the mixture at a rate of about0.830 part/minute for 58 minutes. The S rate was reduced to about0.1-0.14 part/minute and methanol, water and acetic acid were distilledolf. The mixture was cooled to 85 C. and about 5 parts of water wereadded. The mixture was then refluxed until 11 parts of liquid werecollected in the water collector. This sequence of cooling, adding about5 grams of water followed by refluxing and then collecting a liquid wasrepeated two more times; 8.2 parts of liquid were collected the firsttime and 6.2 parts were collected the second time. The total time duringwhich the sulfur dioxide was introduced into the mixture at a reducedrate during this sequence was 5.33 hours. At the end of this time sulfurdioxide treatment was discontinued and nitrogen was passed into themixture; the mixture was then heated to 143 C. to remove the remainingwater. The mixture was cooled and then diluted with about 200 parts ofbenzene. This mixture was filtered through a bed of Celite Filteraid.The solvents were then removed under vacuum. The product thus obtainedwas a clear fluid; the yield was 146 parts. Analysis showed it tocontain 27.8% Ba and 7.37%

S. The infrared spectrum showed the presence of some acetate.

EXAMPLE 14 A vessel fitted as in Example 1 was charged with 75.6 parts(0.4 mole) of black ash (89.6% assay) followed by about 100 parts ofwater. To this mixture 60 parts (1.0 mole) of glacial acetic acid wasgradually added with stirring over a 7-minute period. The reactionmixture was then heated at reflux for 8 hours. At the end of this time asolution of 46.75 parts (0.1 mole) of a 0 olefin sulfonic acid(Saponification No.==130), 30 parts pale oil and about 40 parts naphtha.This mixture was heated at reflux for 30 minutes, cooled to 60 C. andabout 4 grams of methanol were added. Sulfur dioxide was passed into themixture at a rate of about 0.830 part/minute for 52 minutes at areaction temperature ranging from 58 C.-72.5 C. The sulfur dioxide flowwas then reduced to 0.1 part/minute and water, acetic acid and methanolwere distilled off. The treatment time with sulfur dioxide at thereduced rate was about 4 hours. The sulfur dioxide flow was discontinuedwhen the temperature of the mixture reached 139 C. The temperature wasthen raised to 150 C. to remove the remaining water. After cooling themixture, it was diluted with about 200 grams of benzene. This productmixture was then filtered through a bed of Celite Filter-aid. Thesolvents were removed under vacuum. The overbased barium productobtained was a cloudy fluid. The yield was 143.9 parts. Analysis showedit to contain 31% Ba and 8.11% S. The infrared spectrum showed someacetate present.

The olefin sulfonic acid used in Examples 11-14 was obtained by S0;.,sulfonating the C olefin composition G of Table 2.

Similar overbased products are obtained when ethanol or pentanol is usedin place of methanol in the above examples. Sulfonic acids prepared fromolefins disclosed herein also produce overbased barium productsanalogous to those of the examples above. Similar results are alsoobtained if toluene, n-butylbenzene, catalytic reformate mixtures,aviation alkylates, light refining oils, or other suitable petroleumrefinery streams are used in place of the pale oil/naphtha medium in theexamples above. Similar products are also obtained when the examplesabove are carried out at C. and under pressure where necessary.

The overbased barium olefin sulfonate products of the present inventionare useful as additives to distillate hydrocarbon fuels. Thesedistillate fuels include residual fuel oils, home heating fuels,kerosene, and the like. In distillate fuels, these overbased bariumadditives may act as sludge dispersants, corrosion inhibitors orcombustion improvers. An especially important use for these overbasedbarium olefin sulfonates is as smoke suppressing additives in distillatefuels; and particularly in fuels used for internal combustion engines.These overbased sulfonates are especially effective in diesel fuels.Suitable diesel fuels are Federal Specification VV-F-SOO, Grades DF-A,DF-l, DF-2, and DF-4 was well as Classes 1, 2, 3, and 4 diesel fuels.Marine diesel fuel oils are also improved by the overbased sulfonates ofthe present invention. A tabulation of useful distillate fuel oils ispresented in Fuels and Lubricants, Milosh Popovich and Carl Hering,pages 134; 146-453, John Wiley and Sons, Inc., New York (1959).

The useful concentrations for these overbased barium sulfonates indistillate fuels will vary. Concentration ranging from about 0.05% toabout 3% by weight, for example, are useful for suppressing smoke.

These distillate fuel compositions constitute another embodiment of thepresent invention. Following the example of the such distillate fuelcompositions; all percentages are by weight unless otherwise noted.

EXAMPLE 15 A distillate fuel composition is prepared by adding 0.5% ofth product of Example 5 to a No. 2 burner fuel oil (FederalSpecification VV-F-815).

EXAMPLE 16 A distillate fuel composition is prepared by adding 2.5% ofthe product of Example 7 to a No. 6 burner fuel oil (FederalSpecification VV-F-815) EXAMPLE 17 A distillate fuel composition isprepared by adding 1.0% of the product of Example 6 to a No. 5 burnerfuel oil (Federal Specification IV-P 815).

EXAMPLE 18 A distillate fuel composition is preparedby adding 0.2% ofthe product of Example 4 to kerosene.

EXAMPLE 19 A distillate fuel composition is prepared by adding 1.5% ofthe product of Example 1 to a No. 1 burner fuel oil (FederalSpecification VV-F-815).

EXAMPLE 20 A distillate fuel composition is prepared by adding 0.05% ofthe product of Example 8 to a No. 4 burner fuel oil (FederalSpecification VV-F-815) EXAMPLE 21 A diesel fuel composition is preparedby adding 0.05 of the product of Example 2 to a Class 1 diesel fuel.

EXAMPLE 22 A diesel fuel composition is prepared by adding 3% of theproduct of Example 4 to a Class 2 diesel fuel.

EXAMPLE 2 3 A diesel fuel composition is prepared by adding 0.07% of theproduct of Example 1 to a Class 3 diesel fuel.

13 EXAMPLE 24 EXAMPLE 25 A diesel fuel composition is prepared by adding2.5% of the product of Example to a Grade DF-A diesel fuel.

EXAMPLE 26 I A diesel fuel composition is prepared by adding 0.15% ofthe product of Example 7 to a marine diesel fuel.

EXAMPLE 27 A diesel fuel composition is prepared by adding 0.25% of theproduct of Example 8 to a Class 3 diesel fuel.

EXAMPLE 28 A diesel fuel composition is prepared by adding 0.2% of theproduct of Example 1 to a Class 4 diesel fuel.

EXAMPLE 29 A diesel fuel composition is prepared by adding 0.3% of theproduct of Example 8 to a Class 1 diesel fuel.

EXAMPLE 30 A diesel fuel composition is prepared by adding 0.4% of theproduct of Example 9 to a Class 2 diesel fuel.

EXAMPLE 31 A diesel fuel composition is prepared by adding 0.5% of theproduct of Example 11 to a 30 cetane number diesel fuel.

EXAMPLE 32 A diesel fuel composition is prepared by adding 1.0% of theproduct of Example 13 to a Class 3 diesel fuel.

EXAMPLE 3 3 A- diesel fuel composition is prepared by adding 1.5% of theproduct of Example 14 to a marine diesel fuel.

EXAMPLE 34 A diesel fuel composition is prepared by adding 0.7% of theproduct of Example 12 to a Grade DF-4 diesel fuel.

The distillate fuel compositions of the present invention may containother additives such as cetane improvers, cold flow improvers,antioxidants, dyes and the like.

The overbased barium sulfonates of'the present invention reduce thesmoking tendency of distillate fuels. For example, noticeably less smokeis emitted from a diesel engine when it is operating on the fuelcomposition of Example 27 than when operating on Class 3 diesel fuelwhich does not contain the overbased barium sulfonates of the presentinvention. Similarly, less smoke is produced when using the burner fuelcomposition of Example 7 than when using No. 5 burner fuel which doesnot contain the overbased product of the present invention.

The smoke reducing eifect of the overbased barium olefin sulfonates ofthe present invention was determined in a diesel engine test using theHartridge smoke meter for the smoke measurements. The procedure involvedrunning the engine under a certain set of conditions, first with thebase diesel fuel containing no smoke reducing additive. The smoke numberfor this base fuel was set at 100% relative smoke. The smoke numbers ofthe base fuel containing a barium additive of the present invention aswell as the base fuel containing a commercial smoke reducer were thendetermined under the same conditions. The smoke numbers of the fuelscontaining the additives were then compared to the base diesel fuelsmoke number. The relationship of these smoke numbers was then expressedin terms of percent relative smoke.

14 Data obtained for such a series of tests is tabulated below. The basediesel fuel used wasa commercial No. 2 distillate.

TABLE 6.EFFEOT OF ADDITIVES ON DIESEL FUEL SMOKE B A commercial bariumcontaining smoke reducing diesel fuel additive.

The data clearly show that the overbased product of the presentinvention (Example 4) is a very effective smoke reducer in diesel fuel;and is slightly better than a commerical barium-containing diesel smokereducer. This data is representative of the smoke reducing effectivenessof the overbased barium products of the present invention.

Commercial diesel fuels containing about 0.4% by weight of the productof Example 8 or the product of Example 12 were also shown to haveacceptable resistance to water emulsification, as measured by anaccepted commercial resistance-to-emulsification test.

The present invention encompasses three embodiments:

(1) a procedure for preparing overbased barium olefin sulfonates,

(2) the overbased barium olefin sulfonate product, and

(3) the use of these overbased products in distillate fuels.

All three embodiments have been fully described in the foregoingdisclosure and it is desired to limit this invention only within thespirit and scope of the following claims.

I claim:

1. A process for preparing an overbased barium sulfonate whichcomprises:

(1) preparing a mixture of barium sulfide in from about to about 800parts by weight of C -C alkanol per mole of barium sulfide, adding atleast an equimolar amount of water based on barium sulfide and at least2 moles of acetic acid per mole of barium sulfide,

(2) heating said mixture to reflux and maintaining said temperatureuntil the evolution of H 8 has substantially stopped,

(3) adding thereto a mixture of an inert hydrocarbon medium and anolefin sulfonic acid, prepared by sulfonating a mixture of acylic,monoolefins having from about 12 to about 32 carbon atoms, such that themolar ratio of barium sulfide to said sulfonic acid is from about 1:1 toabout 10:1,

(4) introducing sulfur dioxide gas into the heated mixture of Step (3)until the sulfur dioxide efiluent rate is substantially equal to thesulfur dioxide input rate, and

'(5) distilling substantially all the alkanol, acetic acid and waterfrom said mixture.

2. The process of claim 1 wherein said barium sulfide is a crude bariumsulfide.

3. The process of claim 2 wherein said molar ratio of barium sulfide:olefin sulfonic acid is from 2:1 to 5:1, and said alkanol is methanol.

4. The process of claim 3 wherein said mixture of olefins comprises evencarbon numbered olefins containing less than about 3% by weight of C andlower olefins wherein at least 50% of the olefins are alpha olefins.

5. The process of claim 4 wherein said molar ratio of bariumsulfide:sulfonic acid is 3:1 to 4:1.

6. The process of claim 3 wherein said mixture of olefins comprises byweight 0-6% C and lower olefins, a trace-22% C olefins, 32-55% Colefins, 18-39% C olefins, 616% C olefins, 0.5% C olefins, and 0-10% Cand higher olefins, wherein the distribution of olefin configuration insaid mixture is 10-32% internal, 30-55% vinyl, and 30-55% vinylidene.

7. The process of claim 6 wherein said molar ratio of bariumsulfidezsulfonic acid is 3:1 to 4:1.

8. The product prepared by the process of claim 1. 9. The productprepared by the process of claim 2. 10. The product prepared by theprocess of claim 4. 11. The product prepared by the process of claim 6.12. The product prepared by the process of claim 7. I 13. A distillatefuel oil containing from 0.5-3% by weight of the product prepared by theprocess of claim 1. 14. A diesel fuel containing a smoke reducingquantity of the product prepared by the process of claim 1.

15. A diesel fuel containing a smoke reducing quantity of the productprepared by the process of claim 2.

16. A diesel fuel containing a smoke reducing quantity of the productprepared by the process of claim 3.

17. A diesel fuel containing a smoke reducing quantity of the productprepared by the process of claim 4.

1 6 18. A diesel fuel containing a smoke reducing quantity of theproduct prepared by the process of claim 5.

19. A diesel fuel containing a smoke reducing quantity of the productpreparedby the process of claim 6.

20. A diesel fuel containing a smoke reducing quantity of the productprepared by the process'of claim 7.

References Cited UNITED STATES PATENTS 2,763,615 9/1956 Faust 252-333,437,465 4/1969 LeSuer 44-51 DANIELE. WYMAN, Primary Examiner A WILLIAMJ. SHINE, Assistant Examiner US. (:1. X.R.

mg UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.580,707 Dated May 97 I -(g) Warren L. Perilstein It is certified that:error appears in the above-identified patent and that said LettersPatent are hereby corrected as shown below:

In Column 3 Table t, under "Q", "Internal, "30.2 should In Column 4,Table L, footnote explanations '(b) and "(c) should be reversed;

In Column 7, line 1%, sulfifide should be sulfide In Column 8, line 6,"glacidal" should be glacial In Column 8, line 9, "as" should be of InColumn 8, lines 58-59, "about the same.) The S0 feed was then reduced toabout fluxing. should be about 7.5 parts of aqueous material wascollected on refluxing.

In Column 12, lines 5233, "the example of the such" should be areexamples of such In Column 14, Claim 6, line 75, "o.5/o 0 should beSigned and sealed this 12th day of October 1971.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GO'I'TSCHALK Attesting Officer ActingCommissioner of Patents

